Punch gun

An explosive actuated tool for cutting clean holes in a sheet material workpiece comprising:

• a body portion provided with a main bore and having a pistol grip handle integral with the body portion,
• said main bore having a closed end and a vented end, and a cartridge chamber in a wall of the main bore adjacent to said closed end,
• a firing mechanism which includes a locking ring mounted on the tool body for rotation about the longitudinal axis of the main bore between a first position which opens the cartridge chamber for loading through an opening in the periphery of said ring and a second position which closes the cartridge chamber for firing, a trigger mechanism mounted adjacent to the handle and cartridge firing means between the cartridge chamber and the trigger mechanism, at least a portion of the cartridge firing means being carried by the locking ring, said portion being alternately operable and inoperable by said trigger mechanism in the locking ring second and first positions, respectively, and workpiece engaging elements including:
• a piston movably mounted in the main bore and spaced from said closed end to provide a firing chamber,
• a piston rod extending from the piston through the closed end wall, and
• a punch and die both operatively associated with the piston rod and adapted to be assembled on opposite sides of a workpiece.

An explosive actuated tool for cutting sheet metal comprising:

• a body provided with a main bore having a closed end and a vented end and a cartridge chamber communicating with the main bore;
• a piston mounted in the main bore and movable toward said vented end by an explosive force of a cartridge in said cartridge chamber;
• a punch and die operable by movement of said piston to cut said sheet metal;
• and
• a firing mechanism to fire said cartridge, said firing mechanism including a trigger mechanism mounted on the body, cartridge firing means between said cartridge chamber and said trigger mechanism, and a locking member mounted on said body for movement between a first radial position on said tool body which opens the cartridge chamber for loading and a second radial position on said tool body which closes the cartridge chamber for firing, at least a portion of the cartridge firing means being carried by the locking member, said portion being alternately operable and inoperable to fire a cartridge in said cartridge chamber in the locking member second and first positions, respectively.